﻿// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Drawing;
using System.Drawing.Drawing2D;

namespace System.Windows.Forms;

internal class ToolStripProfessionalLowResolutionRenderer : ToolStripProfessionalRenderer
{
    public ToolStripProfessionalLowResolutionRenderer()
    {
    }

    internal override ToolStripRenderer? RendererOverride
    {
        get
        {
            return null;
        }
    }

    protected override void OnRenderToolStripBackground(ToolStripRenderEventArgs e)
    {
        if (e.ToolStrip is ToolStripDropDown)
        {
            base.OnRenderToolStripBackground(e);
        }
    }

    protected override void OnRenderToolStripBorder(ToolStripRenderEventArgs e)
    {
        if (e.ToolStrip is MenuStrip)
        {
            return;
        }
        else if (e.ToolStrip is StatusStrip)
        {
            return;
        }
        else if (e.ToolStrip is ToolStripDropDown)
        {
            base.OnRenderToolStripBorder(e);
        }
        else
        {
            RenderToolStripBorderInternal(e);
        }
    }

    private static void RenderToolStripBorderInternal(ToolStripRenderEventArgs e)
    {
        Rectangle bounds = new(Point.Empty, e.ToolStrip.Size);
        Graphics g = e.Graphics;

        // have to create a pen here because we're not allowed to modify the SystemPens.
        using Pen p = new(SystemColors.ButtonShadow)
        {
            DashStyle = DashStyle.Dot
        };

        bool oddWidth = ((bounds.Width & 0x1) == 0x1);
        bool oddHeight = ((bounds.Height & 0x1) == 0x1);
        int indent = 2;

        // top
        g.DrawLine(p, bounds.X + indent, bounds.Y, bounds.Width - 1, bounds.Y);
        // bottom
        g.DrawLine(p, bounds.X + indent, bounds.Height - 1, bounds.Width - 1, bounds.Height - 1);

        // left
        g.DrawLine(p, bounds.X, bounds.Y + indent, bounds.X, bounds.Height - 1);
        // right
        g.DrawLine(p, bounds.Width - 1, bounds.Y + indent, bounds.Width - 1, bounds.Height - 1);

        // connecting pixels

        // top left connecting pixel - always drawn
        g.FillRectangle(SystemBrushes.ButtonShadow, new Rectangle(1, 1, 1, 1));

        if (oddWidth)
        {
            // top right pixel
            g.FillRectangle(SystemBrushes.ButtonShadow, new Rectangle(bounds.Width - 2, 1, 1, 1));
        }

        // bottom connecting pixels - drawn only if height is odd
        if (oddHeight)
        {
            // bottom left
            g.FillRectangle(SystemBrushes.ButtonShadow, new Rectangle(1, bounds.Height - 2, 1, 1));
        }

        // top and bottom right connecting pixel - drawn only if height and width are odd
        if (oddHeight && oddWidth)
        {
            // bottom right
            g.FillRectangle(SystemBrushes.ButtonShadow, new Rectangle(bounds.Width - 2, bounds.Height - 2, 1, 1));
        }
    }
}
